• 제목/요약/키워드: Starting Method

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기동시뮬레이션 방법에 의한 유도전동기 기동방식 선정 (Selection of Motor Starting Method by Numeric Simulation)

  • 장중구;서상진;이민용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 B
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    • pp.817-820
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    • 2002
  • Since a squirrel cage induction motor by NEMA Design types is designed to withstand full-voltage starting, direct starting method can be the most economical one. Starting a squirrel cage motor from standstill by connecting it directly across the line may allow inush currents of approximately 500-600% of rated current at lagging power factor of 35-50%. For many of the large motors, the starting inrush current may be great enough to cause voltage dips, which may adversely affect the building's lighting system. Electric utilities also have restrictions on starting currents, so that voltage fluctuations can be held to prescribed limits. Therefore the need for choosing the most appropriate method of motor starting is quite essential. In this paper, we proposed a plan for the selection of the most appropriate motor starting method, first by way of numeric simulation using manufacturer's data and second by way of actual experience. So far, more often than not, the selection of motor starting method has been accomplished only as regards to the capacity of the motor and the frequency of starting and stopping. But nowadays such high-tech apparatus as soft starters are being developed, and we are on the position to give more attention to clarify the way of selection of the motor starting method.

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고유모드 계산을 위한 초기 반복벡터의 효율성 연구 (Investigation of Efficiency of Starting Iteration Vectors for Calculating Natural Modes)

  • 김병완;경조현;홍사영;조석규;이인원
    • 한국소음진동공학회논문집
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    • 제15권1호
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    • pp.112-117
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    • 2005
  • Two modified versions of subspace iteration method using accelerated starting vectors are proposed to efficiently calculate free vibration modes of structures. Proposed methods employ accelerated Lanczos vectors as starting iteration vectors in order to accelerate the convergence of the subspace iteration method. Proposed methods are divided into two forms according to the number of starting vectors. The first method composes 2p starting vectors when the number of required modes is p and the second method uses 1.5p starting vectors. To investigate the efficiency of proposed methods, two numerical examples are presented.

구조물의 고유모드 해석을 위한 가속화된 초기벡터 구성기법 (Accelerated Starting Vectors for Analysis of Natural Modes of Structures)

  • 김병완;정형조;이인원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.784-787
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    • 2004
  • Modified version of subspace iteration method using accelerated starting vectors is proposed to efficiently calculate free vibration modes of structures. Proposed method employs accelerated Lanczos starting vectors that can reduce the number of iterations in the subspace iteration method. Proposed method is more efficient than the conventional method when the number of required modes is relatively small. To verify the efficiency of proposed method, two numerical examples are presented.

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터보 블로워용 고속 유도전동기의 새로운 기동방법 (Novel Starting Method of High Speed Induction Motor for Turbo Blowers)

  • 이진우
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2016년도 전력전자학술대회 논문집
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    • pp.253-254
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    • 2016
  • This paper proposes a novel starting method of a high speed induction motor with air bearings for turbo blowers. The friction of air bearings varies according to rotating speed, operating temperature and usage time. Specially, friction torque at initial starting state under low bearing temperature usually results in starting failures of the conventional V/F control method. Therefore, this paper proposes a new starting method, which consists of an initial I/F control mode and smooth transition method to V/F control mode to overcome the starting failure. The experimental results are shown to verify the analysis and the usefulness of the proposed method.

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압축기용 BLDC 전동기의 센서리스 기동 (Position Sensorless Starting of BLDC Motor for Compressor)

  • 이광운;이준환;최재영
    • 전력전자학회논문지
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    • 제11권5호
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    • pp.440-446
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    • 2006
  • BLDC 전동기와 같은 영구자석 전동기는 토크 각에 따라 출력 토크의 변화가 크기 때문에 원활한 기동 특성을 얻기 위해서는 회전자의 초기 위치 정보가 필수적으로 요구된다. 본 논문에서는 냉장고용 왕복동 압축기의 구동을 위해 사용되는 BLDC 전동기의 센서리스 구동장치에서 원활한 기동 특성을 얻기 위한 새로운 기동 제어 방식을 제안한다. 제안된 방식은 전동기의 전류 응답 특성으로부터 파악된 회전자 위치 정보를 이용하여 BLDC 전동기를 기동하는 방식으로, 압축기의 기동 부하 변동에 강인한 기동 특성을 가진다. 실험을 통하여 제안된 방식의 효과를 입증하였다.

포화성분을 고려한 3상 유도전동기 리액터 기동 특성 분석 (Characteristics Analysis for Reactor Starting Method of 3-Phase Induction Motor Considering Saturation)

  • 김종겸
    • 조명전기설비학회논문지
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    • 제26권8호
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    • pp.65-70
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    • 2012
  • Induction motor is the most widely used to obtain the driving force in the industrial site. Induction motor generates a high current at startup. Most of starting currents are often more than five times of rated current. This high starting current can cause problems such as the voltage drop in the system. In order to solve these problems, if the motor capacity is large, generally we use reactor starting method rather than direct on line starting method. When a high startup current passes through reactor, reactor can serve as a nonlinear elements. In this study, we analyzed that the current, torque and power of the induction motor are different from the change of linear and nonlinear components of the reactor magnetic field.

폐루프 방식의 속도 적분각을 이용한 PMSM 센서리스 초기기동 알고리즘 (Closed Type Initial Starting Algorithm for PMSM Sensorless Control Using Integrated Speed Angle)

  • 박성명;김준석
    • 전력전자학회논문지
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    • 제27권1호
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    • pp.18-25
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    • 2022
  • The cold staring issue of permanent magnet synchronous motors (PMSM) is a chronic problem in the field of PMSM sensorless drives. A traditional starting method, called the I-F method, is widely adopted because of its simple structure. However, when using this method, the pre-defined magnitude and frequency of the starting current should be changed according to the condition of the load and machine inertia. In this paper, a smart and simple algorithm for the cold starting of PMSM is proposed. In the proposed method, an integrated control angle from the estimated electrical rotor speed is used for vector control such as the indirect vector control of the induction machine. Thus, very stable cold starting is performed regardless of the machine load condition or inertia changing.

기동 방법에 따른 단상 SRM의 토크 특성 해석 (The Torque Characteristics Analysis of the Single-Phase Switched Reluctance Motor According to the Starting Method)

  • 김준호;김일중
    • 조명전기설비학회논문지
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    • 제26권9호
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    • pp.40-46
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    • 2012
  • The single-phase switched reluctance motor(SRM) has only one inductance variation and the positive torque is generated in the restricted section. So, it cannot be started by itself. To solve this problem, many researchers have addressed the several starting method for the single-phase SRM. This paper is focused on the torque characteristics of the single-phase SRM according to starting method. The four major starting method - permanent magnet, saturable stator pole, to grade the rotor, stepped rotor pole - is selected to analyze the torque characteristics. The analysis model of each starting method is designed to changed the pole shape or inserting other material in the basic model. The torque characteristics of each analysis model is obtained by using FEM analysis. The FEM analysis is performed at incremental rotor positions over half inductance cycle in any one pole with 250AT, 500AT, 750AT. The distortion factor of each analysis model is analyzed through the FFT to compare the distortion between basic model and four analysis model.

고압 유도전동기 역률 보상설비의 특성 해석 (A Characteristic Study on the Power Factor Compensation Application of High Voltage Induction Motor)

  • 김종겸;박영진;이은웅
    • 전기학회논문지P
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    • 제57권3호
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    • pp.225-230
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    • 2008
  • Reactor starting method has the advantage of simplicity and closed transition in spite of lower starting torque per kVA. This method allows a smooth start with almost no observable disturbance on transition and is suitable for applications such as centrifugal pumps or fans. Reactive power doesn't contribute to work but needs to sustain the electromagnetic field required for the induction motor to operate. Starting power factor of induction motor is specially lower than running power factor. Power factor application is needed to compensate for the lower power factor of induction motor. This power factor compensation systems is occasionally being hit by the effects of the starting reactor connection position at the starting, stopping of high-voltage induction motor. This paper describes voltage and current stress affected by the installation position of power factor compensation application at the reactor starting method.

리액터 기동 운전시 콘덴서 전압 특성 해석 (Analysis of Power Condenser Voltage Characteristics by Reactor Starting-operation)

  • 김종겸;박영진;이은웅;이동주;김일중
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.619-620
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    • 2008
  • Reactor starting method has the advantage of simplicity and closed transition in spite of lower starting torque per kVA. This method allows a smooth start with almost no observable disturbance on transition and is suitable for applications such as centrifugal pumps or fans. Starting power factor is specially low. Power factor application is needed to compensate for the lower power factor of induction motor. This power factor compensation systems is being hit by the effects of the starting reactor connection position. This paper describes voltage and current stress affected by the installation position of power factor compensation application at the reactor starting method.

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